class_docstr: ``AsyncCheckpointIO`` enables saving the checkpoints asynchronously in a thread.
  
  .. warning::  This is an :ref:`experimental <versioning:Experimental API>` feature.
  
  Args:
      checkpoint_io: A checkpoint IO plugin that is used as the basis for async checkpointing.
docstr: This method is called to close the threads.
docstr_tok: ["This","method","is","called","to","close","the","threads","."]
code: def teardown(self) -> None:
      """This method is called to close the threads."""
      self._executor.shutdown(wait=True)
  
      # if an error was raised anytime in any of the `executor.submit` calls
      if self._error:
          raise self._error
  
file_path: pytorch-lightning/src/lightning/pytorch/plugins/io/async_plugin.py
imports: from concurrent.futures import ThreadPoolExecutor
  from typing import Any, Optional
  from typing_extensions import override
  from lightning.fabric.plugins import CheckpointIO
  from lightning.pytorch.plugins.io.wrapper import _WrappingCheckpointIO
label_desc: Use image node_id 3 for calling the AsyncCheckpointIO obj's underlying member method code with example usage: obj.teardown() without return types